131 lines
3.8 KiB
C
131 lines
3.8 KiB
C
|
|
/** \file
|
|
|
|
\brief Code specific to the SSD1306 display.
|
|
*/
|
|
|
|
#include "display.h"
|
|
|
|
#if defined TEACUP_C_INCLUDE && defined DISPLAY_TYPE_SSD1306
|
|
|
|
#include "displaybus.h"
|
|
#include "font.h"
|
|
|
|
|
|
static const uint8_t PROGMEM init_sequence[] = {
|
|
0x00, // Command marker.
|
|
0xAE, // Display off.
|
|
0xD5, 0x80, // Display clock divider (reset).
|
|
0xA8, 0x1F, // 1/32 duty.
|
|
0x40 | 0x00, // Start line (reset).
|
|
0x20, 0x02, // Page addressing mode (reset).
|
|
0x22, 0x00, 0x03, // Start and end page in horiz./vert. addressing mode[1].
|
|
0x21, 0x00, 0x7F, // Start and end column in horiz./vert. addressing mode.
|
|
0xA0 | 0x00, // No segment remap (reset).
|
|
0xC0 | 0x00, // Normal com pins mapping (reset).
|
|
0xDA, 0x02, // Sequental without remap com pins.
|
|
0x81, 0x7F, // Contrast (reset).
|
|
0xDB, 0x20, // Vcomh (reset).
|
|
0xD9, 0xF1, // Precharge period.
|
|
0x8D, 0x14, // Charge pump.
|
|
0xA6, // Positive display.
|
|
0xA4, // Resume display.
|
|
0xAF // Display on.
|
|
};
|
|
// [1] Do not set this to 0x00..0x07 on a 32 pixel high display, or vertical
|
|
// addressing mode will mess up. 32 pixel high displays have only 4 pages
|
|
// (0..3), still addressing logic accepts, but can't deal with the 0..7
|
|
// meant for 64 pixel high displays.
|
|
|
|
/**
|
|
* Initializes the display's controller configuring the way of
|
|
* displaying data.
|
|
*/
|
|
void display_init(void) {
|
|
uint8_t i;
|
|
|
|
displaybus_init(DISPLAY_I2C_ADDRESS);
|
|
|
|
for (i = 0; i < sizeof(init_sequence); i++) {
|
|
// Send last byte with 'last_byte' set.
|
|
displaybus_write(init_sequence[i], (i == sizeof(init_sequence) - 1));
|
|
}
|
|
}
|
|
|
|
/**
|
|
Clear the screen. As this display supports many sophisticated commands,
|
|
but not a simple 'clear', we have to overwrite the entire memory with
|
|
zeros, byte by byte.
|
|
*/
|
|
void display_clear(void) {
|
|
uint16_t i;
|
|
|
|
// Set horizontal adressing mode.
|
|
displaybus_write(0x00, 0);
|
|
displaybus_write(0x20, 0);
|
|
displaybus_write(0x00, 1);
|
|
|
|
// Write 512 zeros.
|
|
displaybus_write(0x40, 0);
|
|
for (i = 0; i < 512; i++) {
|
|
displaybus_write(0x00, (i == 511));
|
|
}
|
|
|
|
// Return to page adressing mode.
|
|
displaybus_write(0x00, 0);
|
|
displaybus_write(0x20, 0);
|
|
displaybus_write(0x02, 1);
|
|
}
|
|
|
|
/**
|
|
Sets the cursor to the given position.
|
|
|
|
\param line The vertical cursor position to set, in lines. First line is
|
|
zero. Line height is character height, which is currently
|
|
fixed to 8 pixels.
|
|
|
|
\param column The horizontal cursor position to set, in pixels. First
|
|
column is zero.
|
|
*/
|
|
void display_set_cursor(uint8_t line, uint8_t column) {
|
|
|
|
// Enter command mode.
|
|
displaybus_write(0x00, 0);
|
|
// Set line.
|
|
displaybus_write(0xB0 | (line & 0x03), 0);
|
|
// Set column.
|
|
displaybus_write(0x00 | (column & 0x0F), 0);
|
|
displaybus_write(0x10 | ((column >> 4) & 0x0F), 1);
|
|
}
|
|
|
|
/**
|
|
Prints a character at the current cursor position.
|
|
|
|
\param data The character to be displayed.
|
|
*/
|
|
void display_writechar(uint8_t data) {
|
|
uint8_t i, index = data - 0x20;
|
|
|
|
// Write pixels command.
|
|
displaybus_write(0x40, 0);
|
|
|
|
// Send the character bitmap.
|
|
#ifdef FONT_IS_PROPORTIONAL
|
|
for (i = 0; i < pgm_read_byte(&font[index].columns); i++) {
|
|
#else
|
|
for (i = 0; i < FONT_COLUMNS; i++) {
|
|
#endif
|
|
displaybus_write(pgm_read_byte(&font[index].data[i]), 0);
|
|
}
|
|
// Send space between characters.
|
|
for (i = 0; i < FONT_SYMBOL_SPACE; i++) {
|
|
// TODO: we finalise a I2C (or other) bus message after each character
|
|
// here because we have no idea on how many more are following. This
|
|
// is highly inefficient and makes the displaybus buffer almost
|
|
// pointless.
|
|
displaybus_write(0x00, (i == FONT_SYMBOL_SPACE - 1));
|
|
}
|
|
}
|
|
|
|
#endif /* TEACUP_C_INCLUDE && DISPLAY_TYPE_SSD1306 */
|